hAVING THE 335i, i can tell you that the engine sound with the hood open on the 6 cyl DOES NOT sound as sweet as on previous 6cyl 3 series.
Both current F30 N20 and N55 sound terrible claking and rattling due to the turbo affixed.

eXHAUSt-wise, the 328i would be less melodious than the 335i.
The 335i is bordeline hooligan with its exhaust, (although not as much as the G35/37)

If you want the quietest car possible, you should consider Lexus or the 7 series...

Some of my family members complain that my 335i is loud and not "refined" and they equate that to being not good value for $ spent. They say that x car is quieter and costs less. I'm a car guy and I don't care what they say. If I wanted that, Lexus would have been my pick, but then I might die of boredom.

Choosing a car is like choosing a girl friend. Do you pick a girl because she's punctual? Or do you pick the girl who makes you smile every time you see her?

Some of my family members complain that my 335i is loud and not "refined" and they equate that to being not good value for $ spent. They say that x car is quieter and costs less. I'm a car guy and I don't care what they say. If I wanted that, Lexus would have been my pick, but then I might die of boredom.

Choosing a car is like choosing a girl friend. Do you pick a girl because she's punctual? Or do you pick the girl who makes you smile every time you see her?

The F30 3 series are almost priced the same as 5 anyway. ($40k for 328/528, $50k for 335/535)

Wut? 328i starts at 37k msrp. 528 at 47k. That's a 10k gap. Or a 25% price gap. You could get premium, tech, cold weather, and HK audio on a 3 series for a base 5.

MSRP is not the whole story.
Because the 5 series is heavily subsidized. It is common to get $5k to $10k off on a new 5 series(I personally got $9k off). While its hard to find the same deals on the 3.
On top of that, you don't have the 'lines' gimmick, and more stuff comes standard.
Which equals to not much difference in price.
(A good example would be my pretty well optioned MSRP $58k F10 535i, I got it for $49k. While my sports line MSRP $56k F30 335i, I got it for $53k.
In my case, the 535i was $4000 cheaper)

MSRP is not the whole story.
Because the 5 series is heavily subsidized. It is common to get $5k to $10k off on a new 5 series(I personally got $9k off). While its hard to find the same deals on the 3.
On top of that, you don't have the 'lines' gimmick, and more stuff comes standard.
Which equals to not much difference in price.
(A good example would be my pretty well optioned MSRP $58k F10 535i, I got it for $49k. While my sports line MSRP $56k F30 335i, I got it for $53k.
In my case, the 535i was $4000 cheaper)

I don't know dude, seems fishy. I would have to give up many options to get a 5 to the same price level as the 3 I'm looking at right now. ED pricing for both.

EDIT: Just went to BMW USA and for the same options 335i is 13k cheaper than 535i. I don't see how incentives could get that 65k 535i anywhere close to that 52k 335i.